NEW RKR POTENTIAL CURVES FROM EMISSION SPECTRA OF LITHIUM HYDRIDE

Abstract

In order to obtain a better understanding. of the $X^{1}\Sigma^{+}$ ground state and the anomalous $A^{1}\Sigma^{+}$ state potential curves of lithium hydride, the emission spectra of the $A^{1}\Sigma^{+}$ - $X^{1}\Sigma^{+}$ of $^{6}LiH$ and $LiD$ were photographed in the 3300 {\AA}-5000 {\AA} region with a 3.4 m Ebert spectrograph. The bands found Involved $v^{\prime\prime} = 0{-}7$ to various $v^{\prime} = 0{-}16$ as compared to previous investigators, where observed bands Involved only $v^{\prime\prime} = 0, 1,$ and $2, v^{\prime} = 2-13$ for $^{6}LiH;^{1}$ no data were available on $^{6}LiD; v^{\prime\prime} = 0{-}3$ to $v^{\prime} = 15 for ^{7}LiH;^{2}$ and $v^{\prime\prime} = 0, 1, $ and 2, to $v^{\prime} = 1{-}18 $ for $^{7}LiD.^{3}$. The vibrational-rotational analysis of $^{6}LiH$ and $^{6}LiD$ were completed and new RKR (Rydberg-Klein-Rees) potential curves were constructed. The $^{7}LiH$ and $^{7}LiD$ data reported by Crawford and Jorgensen were also reanalyzed. Mass-reduced $analyses^{4}$ are in progress.